This is some of the stuff that Desmos, in the brief six months of its existence, has got to people who can really use it: 500kg of flour; 3.6 tonnes of pasta; 500kg of biscuits and crackers; 1,500 children's books; 100 boxes of cleaning supplies; 200 bags of clothes; 150 bags of toys; 300 litres of juice; 50 boxes of school supplies; and two synthesizers.

"The synthesizers were a bit of a conundrum," says Ekavi Valleras, who used to work in New York for the philanthropy arm of Merrill Lynch but now runs Desmos – the name means bond or link – with four former friends from secondary school, all now in their early 30s and back in Greece after several years studying and working abroad.

"But eventually we found a foundation that worked with autistic children. Some of them could really only express themselves through music. They were delighted with the synths." It's getting easier to match donors and recipients now the charity's bigger; the other day Siemens offered six computers and 10 minutes later Ekavi had an email from a charity that needed them.

Desmos started last November from a conviction, as the crisis really started to bite, that "we just had to do something", says Myrto Anastassopoulos, who like four of the five friends also has a day job (she now works alongside her mother in the family firm). "Giving has never been well organised in Greece, and we wanted to do something to make it easier and more effective."

Niki Kerameus, a lawyer, says that because the sector is underdeveloped, "people who want to give tend to put things in bags and give them to the church. We wanted to see it through, make sure the donation was used in the best possible way, that the recipient got exactly what they needed. It's about maximising efficiency, analysing and meeting specific needs. And we wanted transparency about where gifts end up; we email donors to tell them."

Niki set about establishing the organisation as a non-profit foundation, a lengthy process that will only be completed this month. A husband persuaded his employer, an insurance company, to donate office space. Ekavi, who devotes herself full time to the organisation, began contacting welfare groups to find out what they needed.

Six months later, Desmos helps some 35 different humanitarian and welfare institutions including soup kitchens, shelters for the homeless, orphanages, foundations for children with disabilities, a hostel for women suffering domestic violence, child care units and an association aiding the families of prisoners.

It works by approaching companies – it currently works with about 20, and the number is growing – in two ways. From those that produce things, the women ask for surplus produce or seconds: those 3.6 tonnes of pasta, which went to assorted soup kitchens in the greater Athens region, had marginally imperfect packaging.

Or they hold charity drives, presenting a welfare organisation and its needs to a company's employees, and ask them to donate, say, unneeded clothes, or perhaps to buy an extra cleaning product when they were next at the supermarket and donate it.

"Or sometimes," says Alexia Katsaounis, who also works for her family firm, "a department will pool its money and go to the shop. And we always ask employees to go with us to the welfare organisation. They can give time as well as money. We want to build viable, long-term relationships between givers and receivers."

The four with day jobs reckon they spend up to four hours a day working on Desmos, which has grown at a pace that has taken them aback. "It's really a second job," says Marina Sotiriou, a dentist. Volunteers help, but they urgently need a full-time, permanent person in the office alongside Ekavi. The aim is to hire someone once the charity is officially registered later this month and can legally accept cash donations.

Sometimes welfare organisations come and collect particularly bulky produce from Desmos's office (it aims in the future to have a proper warehouse), but often the women or volunteers deliver using their own transport. That problem, at least, has now been resolved: after a daunting interview process, an Austrian charitable foundation has just told them it will soon be funding a Desmos delivery van and fuel.

• Jon Henley is in Greece telling real people's stories. Please contact him if you have suggestions for people he could see or places he could visit, or send him your personal story (not too long, please). He will post as much as he can on the blog. Jon can be contacted on Twitter (@jonhenley) where the hashtag for this series is #EuroDebtTales, or by email (jon.henley@guardian.co.uk).